Question

Two charges q1, q2 exert some amount of force on each other. What will happen to the force on q1 if another charge q3 is brought close to them?

(a) The force will increase

(b) The force will decrease

(c) The force remains the same

(d) The force may increase or decrease depending on whether q3 is positive or negative

I have been asked this question in exam.

My query is from Coulomb’s Law topic in portion Charges and Fields of Physics – Class 12

Answer 1

The correct choice is (d) The force may increase or decrease depending on whether q3 is positive or negative

Explanation: If both the charges q1 and q2 are positive then they will repel each other. Now if the third charge q3 is also positive, the repulsive force will increase. But if q3 is negative, the repulsive force will be reduced by some amount due to the attractive force between q1 and q3.